Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
  • H02G1/00—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines
  • H02G1/06—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for laying cables, e.g. laying apparatus on vehicle
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16G—BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR
  • F16G11/00—Means for fastening cables or ropes to one another or to other objects; Caps or sleeves for fixing on cables or ropes
  • F16G11/08—Fastenings for securing ends of driving-cables to one another, the fastenings having approximately the same diameter as the cables
  • F16G11/09—Fastenings for securing ends of driving-cables to one another, the fastenings having approximately the same diameter as the cables incorporating hinge joints or pivots for the attachment of the cable ends
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
  • H02G1/00—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines
  • H02G1/02—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for overhead lines or cables
  • H02G1/04—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for overhead lines or cables for mounting or stretching
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
  • H02G1/00—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines
  • H02G1/06—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for laying cables, e.g. laying apparatus on vehicle
  • H02G1/08—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for laying cables, e.g. laying apparatus on vehicle through tubing or conduit, e.g. rod or draw wire for pushing or pulling
  • H02G1/081—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for laying cables, e.g. laying apparatus on vehicle through tubing or conduit, e.g. rod or draw wire for pushing or pulling using pulling means at cable ends, e.g. pulling eyes or anchors
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
  • H02G1/00—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines
  • H02G1/06—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for laying cables, e.g. laying apparatus on vehicle
  • H02G1/08—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for laying cables, e.g. laying apparatus on vehicle through tubing or conduit, e.g. rod or draw wire for pushing or pulling
  • H02G1/083—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for laying cables, e.g. laying apparatus on vehicle through tubing or conduit, e.g. rod or draw wire for pushing or pulling using lines, e.g. needles, rods or tapes
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
  • H02G1/00—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines
  • H02G1/14—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for joining or terminating cables
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
  • H02G15/00—Cable fittings
  • H02G15/08—Cable junctions
  • H02G15/18—Cable junctions protected by sleeves, e.g. for communication cable
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
  • H02G7/00—Overhead installations of electric lines or cables
  • H02G7/18—Devices affording mechanical protection in the event of breakage of a line or cable, e.g. net for catching broken lines

Definitions

• the present invention concerns a connection joint for cables, such as for example electrical conductors, cables, optical fibers, or suchlike, for a cable stringing plant.
• the present invention also concerns a method to produce such a connection joint for cables and also a cable stringing plant comprising the joint.
• the present invention concerns a joint which can be used in a plant to string, for example, a high voltage overhead electric line and in general overhead lines which provide the so-called“braked” stringing of the cables, that is, the overhead conductors.
• the high voltage overhead transmission lines can consist of single conductors (one per phase), but more typically they consist of multiple conductors for each phase, ranging from 2 to 6, but also with a tendency to increase up to 8 or 10 conductors.
• the brake and winch stations are located at opposite ends of a section of the line on which the conductor is being replaced.
• the winch station where the old conductor is recovered can consist of a winch-brake machine for the recovery of the old conductor and a number of reel- stands equal to the number of conductors that make up each single phase of the line.
• the empty reels which will collect the“old” conductor will then be installed on the stands, and the“old” conductor will then be disposed of in suitable recycling centers.
• the brake station where the unwinding and tensioning of the new conductor occurs, or of a pulling cable to be used subsequently for the tensioning of new conductors normally consist of a brake or winch-brake machine and a number of reel-stands equal to the number of conductors that make up each single phase of the line.
• the size of the winch and brake stations is proportional to the number of stands on which the individual reels have to be housed.
• the brake winches for the recovery of the existing conductor normally consist of a pair of capstans for each conductor, provided with a diameter 35 times the diameter of the conductor to be recovered.
• the conductors that make up the high voltage lines have multiple interruptions along their length, essentially due to the presence of fixed joints in the span, the so-called“mid-span joints”. These have the function of connecting the two ends of the conductors in the event of a reel change, or when a reel of new conductor finishes, and the subsequent reel begins.
• the joints consist of straight tubular cores in aluminum and/or steel with a length that varies between 500mm to 2000mm.
• the line for which the conductors are being replaced has variable lengths, but typically is divided into single operative segments, the length of which can vary from 3 to 6 km, as a function of the morphological characteristics of the line and the orographic conditions of the terrain.
• tension supports typically in correspondence with high angles or special conditions such as critical crossings or other, where the conductor is anchored in a horizontal direction and the electric continuity is guaranteed with bypass segments; in the event the tension support does not coincide with the beginning or end of the segment, the so-called through anchor is made, that is, the by-pass is connected to the two branches of the conductor of the line with two end sock joints connected to a swivel joint, or to double sock joints.
• the process is interrupted whenever the new conductor present at the brake station runs out, and therefore it is necessary to replace the reel of new conductor, or when the reel of old conductor is filled at the winch station and an empty reel therefore has to be installed.
• the sizes and stiffness of the fixed mid-span joints are such that they often do not allow their passage even in the stringing pulleys, without the risk of deformation and/or breakage; in the event the conditions of the joint do not guarantee the necessary safety coefficients for the reconductoring operation, the joint itself has to be replaced with a temporary connection made as described above with sock joints, with the same operative sequence.
• “Joint Protectors” can be used, consisting of steel tubular elements divided into two halves, which completely cover the joint itself and protect it during stringing operations; in any case these devices have to also be installed before or during the stringing and have to be removed when they reach the winch station.
• a system to recover conductors is also known from the state of the art, which replaces the traditional winch machine with a so-called continuous pulling system, see for example the Italian patent application number 102016000021986 in the name of the Applicant, able to achieve a continuous stringing eliminating the need to stop the pulling operation when the fixed mid-span joints, or the temporary joints (by-pass) reach the winch machine.
• One purpose of the present invention is to provide a stringing joint for cables, in particular a swivel joint, which can provide a greater degree of flexional freedom than current known swivel joints so that for example it allows rapid, efficient and safe reconductoring operations, and furthermore which is equipped with a longitudinal flexibility such as to allow it to adapt to the circular profiles of the stringing plant, such as for example pulleys or stringing rollers, but also traction wheels of pulling systems, reels or other, minimizing the operating overloads associated with traditional swivel joints.
• Another purpose of the present invention is to provide a connection joint for cables which, in reconductoring operations, offers the possibility of inserting the old or new conductor on each side for a significantly shorter length than is necessary with traditional joints, for example sock joints.
• Another purpose of the present invention is to provide a connection joint for cables which also has a high degree of rotational freedom, similar to or greater than that of current swivel joints.
• Another purpose of the present invention is to provide a connection joint for cables which effectively manages to withstand workloads suitable for the work operations and the operations to maintain the minimum safety coefficients provided for the stringing operations.
• Another purpose of the present invention is to perfect a rapid and efficient method to produce a connection joint for cables for a cable stringing plant.
• Another purpose of the present invention is to provide a cable stringing plant comprising an efficient and flexible connection joint for cables which is highly adaptable to the circular profiles present in the plant, such as for example pulleys, rollers for stringing the cables, but also traction wheels of pulling systems, reels or other.
• the Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.
• one purpose of the invention is a connection joint for cables for a cable stringing plant;
• the joint comprises at least one first tubular element to which a first segment of a flexible member is attached and positioned rotatable, at least with respect to a longitudinal axis of the joint, inside a second tubular element open at a first end and closed at the other end by a bottom wall;
• the bottom wall comprises at least one hole from which a second segment of the flexible member emerges;
• the second segment is attached to a portion of a third tubular element;
• the second and third tubular elements are provided on opposite ends with a corresponding hole directed substantially in a longitudinal direction and able to house a respective segment of cable to be laid.
• a bushing is housed between the first tubular element and the bottom wall of the second tubular element; the bushing has a surface able to rest on a rounded internal part of the bottom wall of the second tubular element; the surface of the bushing has a rounding corresponding to the rounding of the internal part of the bottom wall.
• the bushing is preferably separated from said first tubular element, therefore it is a separate component from the first tubular element.
• the surface of the bushing can also comprise a hemispherical or similar external profile.
• the portion to which the second segment of the flexible member is attached can comprise a polygonal external shape, suitable for example to engage with a clamping tool or suchlike.
• a distance comprised between about 5 mm and about 10 mm is left between the end of the portion to which the second segment of the flexible member is attached and the bottom wall of the tubular element, so as to allow the correct flexion of the joint and to not distance the components of the joint excessively.
• the distance can for example be about 7 mm.
• the tubular elements can be attached to the respective segments of the flexible member by compression on the segments of the flexible member.
• the segments of cable can be attached in the holes of the tubular elements by compression of the segments of tubular elements.
• At least one thrust-bearing member can be positioned between the first tubular element and the bushing.
• the tubular elements can for example be aluminum sleeves, so as to be easily and effectively compressed on the flexible member and on the segments of cable.
• the flexible member can comprise at least one steel cable or cord, in particular a spiral steel cable or cord, which by its very nature is highly flexible and resistant.
• Another purpose of the invention is a method to produce a connection joint for cables for a cable stringing plant, comprising: attaching a first segment of a flexible member to a first tubular element; inserting the first tubular element into a second tubular element, so that the first tubular element is positioned rotatable, at least with respect to a longitudinal axis of the joint, inside the second tubular element; the second tubular element is open at a first end and closed at the other end by a bottom wall; the bottom wall comprises at least one hole from which a second segment of the flexible member emerges; attaching the second segment of the flexible member to a portion of a third tubular element; housing a segment of cable in holes made in a substantially longitudinal direction inside the second and third tubular elements.
• the method provides to house a bushing between the first tubular element and the bottom wall of the second tubular element; the bushing has a surface able to rest on a rounded internal part of the bottom wall of the second tubular element; the surface of the bushing has a rounding corresponding to the rounding of the internal part of the bottom wall.
• Another purpose of the invention is a cable stringing plant, provided with at least one winch machine and at least one brake machine positioned on opposite sides with respect to one or more intermediate supports and comprising at least one connection joint for cables as defined above.
• FIG. 1 is a schematic view of a cable stringing plant according to the present invention.
• - fig. la is a view of an enlarged zone of the plant of fig. 1 in which a connection joint for cables according to the present invention is schematically shown;
• - fig. 2 is a three-dimensional view of the present joint
• - fig. 3 is a view of the present joint seen from one end;
• - fig. 4 is a longitudinal section view of the present joint according to line IV- IV of fig. 3;
• - fig. 4a is a view of an enlarged zone of the joint of fig. 4.
• fig. 1 schematically shows a stringing plant 10, according to the present invention, configured to string one or more cables 11, that is, for example, one or more electrical conductors of a high voltage overhead electric line.
• a cable 11 is schematically shown.
• the stringing plant 10 comprises, to string the cable 11, at least one brake machine 12 and at least one winch machine 14, each of these provided with one or more winding or unwinding members, or capstans 13.
• the brake machine 12 and the winch machine 14 could also be of the winch- brake type, that is, combined in order to selectively perform both the winch function and also the brake function.
• At least one brake machine 12 and at least one winch machine 14 are positioned on opposite sides with respect to intermediate supports 15, for example pylons, on which the cables 11 are strung. In the event machines of the winch-brake type are used, at least one winch-brake machine will be positioned on each side with respect to the intermediate supports.
• the cable 11 is strung on a pulley 16, or a roller, on which, as is known, the cable 11 will be subjected to a certain curvature.
• the cable 1 1 is fed to the stringing plant by means of at least one reel 17 disposed upstream of a brake machine 12 and is recovered downstream of the winch machine 14 on a reel 17.
• a joint 20 is schematically shown along the cable 11, for example in the zone Zl, able to connect two segments of cable l la and 1 lb, see the enlargement of the zone Zl of fig. la.
• the joint 20 see also the views of fig. 2, fig. 3 and fig. 4, comprises a tubular element 18, for example a sleeve, to which a segment 22 of a flexible member 19 is attached.
• the flexible member 19 can be a steel cable or cord, in particular a spiral steel cable or cord, which by its very nature is flexible, therefore guarantees great flexibility to the present joint 20.
• the tubular element 18 can be for example an aluminum sleeve.
• the segment 22 of the flexible member 19 can be inserted inside the tubular element 18 and the tubular element 18 can be compressed, in a known manner, in order to firmly enclose the segment 22 of the flexible member 19, using for example one of the traditional methods to compress mid-span joint for stringing plants.
• the tubular element 18 with the segment 22 of the flexible member 19 attached is introduced into another tubular element 23, which is open at one end 24 and at the opposite end comprises a bottom wall 25 in which a hole 26 is made, see also fig. 4a.
• the hole 26 has a diameter such as to allow the passage of an open segment 27 of the flexible member 19.
• the bottom wall 25 is preferably rounded at least toward the inside of the tubular element 23 and a bushing 28 rests thereon, housed between the bottom wall 25 and the tubular element 18.
• the bushing 28 is therefore preferably an element isolated and separated from the tubular element 18 and, of course, from the tubular element 23. This allows an even greater adaptability of the flexion movements of the joint 20 in the different situations in which it can be used.
• a thrust-bearing member 37 can be provided between the bushing 28 and the tubular element 18, such as for example a thrust bearing or a bushing made of bronze or polymeric material.
• the bushing 28 can be made for example of polymeric material.
• the bushing 28 also has a surface 36 which rests against the rounded internal part of the bottom wall 25 of the tubular element 23; this surface 36 of the bushing 28 has a rounding corresponding to the rounding of the bottom wall 25, so as to allow a minimum flexion movement between the tubular element 18 and the tubular element 23.
• the surface 36 of the bushing 28 can have a semispherical or similar external profile, in order to obtain an effective and optimal distribution of the forces at play during the flexion movements of the joint 20.
• the hole 26 preferably has an internal diameter which is greater than the external diameter of the flexible member 19, in order to facilitate the flexion of the flexible member.
• the hole 26 can be defined by a cylindrical surface diverging from the inside toward the outside of the tubular element 18, as shown in fig. 4 and fig. 4a, in order to facilitate the flexion of the flexible member 19.
• the tubular element 18 is mounted rotatable inside the tubular element 23, which has a hole 29 directed longitudinally, that is, along the longitudinal axis L, in particular the tubular element 18 is free to rotate with respect to the longitudinal axis L of the joint 20.
• the tubular element 18 has a cylindrical external surface which is inserted into the cylindrical hole 29 of the tubular element 23.
• the hole 29 of the tubular element 23 is partly occupied by the tubular element 18 and has at least one free portion, so as to allow the insertion of a segment of cable, for example the segment of cable 11a.
• the external surface 30 of the tubular element 23 located in correspondence with the hole 26 from which the flexible member 19 exits can also have a rounded shape.
• tubular element 31 is attached on the free segment 27 of the flexible member 19 which protrudes out of the tubular element 23 through the hole 26.
• the tubular element 31 comprises a first portion 32 provided with a hole 21 inside which the segment 27 of the flexible member 19 is introduced.
• the tubular element 31 can be an aluminum sleeve.
• the attachment of the segment 27 of the flexible member 19 to the portion 32 can occur in a manner similar to that mentioned previously, by means of known techniques to compress the portion 32.
• the portion 32 which houses the portion 27 of the flexible member 19 can have, after compression, a polygonal external shape, for example hexagonal, as can be seen in fig. 2.
• a certain distance D can be left between the end 33 of the portion 32 and the bottom wall 25 of the tubular element 23, so as to allow the correct flexion of the joint 20.
• the distance D is comprised between about 5 mm and about 10 mm, so as to allow the correct flexion of the joint and to not excessively distance the components of the joint.
• the distance can be for example equal to about 7 mm.
• the bottom wall 25 comprises a rounded external surface 30, it would be possible to provide a corresponding rounding of the end 33 of the portion 32, so as to still allow the correct flexion of the joint 20.
• the tubular element 31 comprises another portion 34 provided with a hole 35, directed longitudinally, inside which a segment of cable can be inserted, for example the segment of cable l ib.
• the tubular elements 23 and 31 can be aluminum sleeves.
• the attachment of the segments of cable 1 la and 1 lb respectively in the hole 29 of the tubular element 23 and in the hole 35 of the tubular element 31 can occur by means of a compression operation performed with the traditional compression methods of mid-span joints, that is, by compression of the tubular elements 23 and 31 on the segments of cable 1 la, l ib.
• the tubular elements 23 and 31 are rectilinear and at least initially and at rest are directed along the longitudinal axis L of the joint 20.
• connection joint 20 for cables equipped with a flexible member 19 and tubular elements 23 and 31 to which to connect the segments of cable 11a and 1 lb, is provided with the flexibility necessary to follow in a spontaneous manner the circular profiles present in the stringing plant 10, for example the profile of the stringing pulleys, compatibly with the sizes of the joint itself and with the size of the diameter of the bottom of the throat of the pulley.
• connection joint 20 also lends itself to be used with devices different from the traditional stringing pulleys, such as stringing rollers or other specific tools, for example traction wheels, reels or other.
• Another aspect of the present joint 20 is that it is temporary, that is, it is a single-use disposable joint: the characteristic of being disposable is possible thanks to the type of construction, that is, the attachment of the flexible member 19 to the tubular elements 18 and 31 occurs by compression of the tubular elements 18 and 31 on respective segments 22 and 27 of the flexible member 19. This characteristic is further obtained by the attachment of the segments of cable 1 la and l ib to the respective tubular elements 23 and 31 by compression of the tubular elements 23 and 31 on the sections of cable 1 la and 1 lb.
• the present joint 20 therefore proves to be completely compatible with the operative method of the innovative continuous pulling system cited in the Italian patent application number 102016000021986.
• traditional swivel joints as mentioned in the introduction, cannot be used in this pulling system, in particular traditional swivel joints cannot pass through the system of traction wheels of the continuous pulling unit due to the reduced length, which does not guarantee a simultaneous grip of at least two traction wheels.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Mutual Connection Of Rods And Tubes (AREA)
• Laying Of Electric Cables Or Lines Outside (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=64755623

Family Applications (1)

Country Status (4)

Citations (6)

Family Cites Families (1)

• 2018
  • 2018-10-05 IT IT102018000009196A patent/IT201800009196A1/it unknown
• 2019
  • 2019-09-25 EP EP19783741.2A patent/EP3861607B1/en active Active
  • 2019-09-25 WO PCT/IT2019/050211 patent/WO2020070764A1/en active Application Filing
  • 2019-09-25 US US17/278,728 patent/US11705697B2/en active Active

Patent Citations (6)

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